Engine simulation programs ??

[mk e]

There has been a lot of refinement in DM over the years. On my engine it says say should be around 106-108 for best overall but as low as 102 works well and it wants more duration in the exhaust lobe than the intake.......I suspect the problems you guys had are gone.

It's just a simulation and results will vary depending g on the setup, but it will help with understanding reversion and such

Edit. DM6 has what seems an odd result with intake length on my engine. It predicts pretty much the same tuned lengths as DM5 did but with DM5 about a 17" length tuned to the 2nd pulse was best but in DM6 shorter tuned lengths are always better - smoother, broader , higher hp curve. It thinks a 6" length (total head +manifold) is best.....there is no way to build that and I don't believe there is any way its true. When dyno day (finally) arrives my plan is to bring 10.25"(4th), 13"(3rd), 16.5" (2nd)stack options and see what there is to see then I promised to send the data back to DM as they were also a little confused at what the sim was spitting out for my engine as well and commented they planned to keep the setup for development as it seemed very sensitive and they'd not seen anything behave quite like it.....which I guess is what you get when you spend many many hours optimizing everything in software as a matched set....the set matches great but any change at all makes it not the matched set.

[pastry_chef]

There has been a lot of refinement in DM over the years. On my engine it says say should be around 106-108 for best overall but as low as 102 works well and it wants more duration in the exhaust lobe than the intake.......I suspect the problems you guys had are gone.

Agree, pleased with 6 recommendations so far.